"""
ThingController.delete()
	deletes things
	deletes all Facts related to a thing
	decrements the count of all questions and answers related to a thing
	decrements the Question.declines of declined Facts
	non owners aren't allowed to delete other people's things
	blobstore photos are deleted
	
MailHandler.thing()
	When a message has an attachment
		Then the created Thing will have a blobstore reference in it's "photo" property
"""